Effect of Spacing on the Flame Propagation Characteristics of PE/Metal Sandwich Insulation Panels

To study the effect of spacing on the flame propagation characteristics of polyethylene (PE)/metal sandwich insulation panels, an experimental platform was built to simulate the ejection of a flame from the opening of a building compartment of a high-rise building, and the effects of different spacings and the presence of hemming were investigated. The flame propagation characteristics were summarized from the three perspectives of the flame height, temperature change, and mass-loss rate. A temperature distribution model was established via the combination of the flame height and temperature change, and a mass-loss model was established to judge the degree of flame propagation. The experimental results are as follows. With the increase of the spacing, the flame height was found to first increase and then decrease, after which it finally reached stability. The front flame height reached the peak at the spacing of 6 cm, and the rear flame height reached the peak at the spacing of 9 cm. With the increase of the spacing, the flame temperature and mass-loss rate were found to first increase and then decrease, and both reached the peak values at the spacing of 6 cm. Moreover, the hemming of the thermal insulation panel was found to hinder the spread of flames to a certain extent.